1. Field of the Invention
The present invention relates to a method of forming branch connection with a flat cable, and in particular to a method of forming electrical connections for connecting an intermediate portion of, for example, a high-speed signal transfer cable to contacts of a connector for branching connection.
2. Description of the Prior Art
Hitherto, to connect intermediate portions of a high-speed signal transfer cable to a connector for branch connection, the cable was cut into two portions 101, 102 as shown in FIG. 14, the leads 101a, 101b, 101c, . . . , 102a, 102b, 102c, . . . , of respective cables 101, 102 being exposed at the cut ends 103, 104 of these cable portions 101, 102; pairs of corresponding leads 101a, 102a; 101c, 102c, . . . , are electrically connected to the end portions of respective contacts 105, 106, 107, . . . , by means of, for example, soldering.
When respective pairs of two signal transfer leads of high-speed signal transfer flat cables are electrically connected to the connecting ends of corresponding contacts in accordance with the above described conventional branch connection forming method, short-circuits or imperfect connections tend to occur since many signal lines without any insulating coating as well as the earth lines are made to cross with each other in a complicated manner.
The present invention has been made in view of the above mentioned point, and an object thereof is to provide a method which makes it possible to form good branch connections of a flat cable easily and securely, and which further makes it possible to reduce the variation in the impedances, even for high-speed signals or signals having very high frequency components, at the branch connections of a transfer system.